 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.actions;

 import org.eclipse.jface.action.Action;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.ui.IPerspectiveDescriptor;
 import org.eclipse.ui.IPluginContribution;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.internal.IWorkbenchHelpContextIds;
 import org.eclipse.ui.internal.util.Util;

 /**
  * Opens a perspective.
  *
  * @since 3.1
  */
 public final class OpenPerspectiveAction extends Action implements
         IPluginContribution {

     /**
      * The perspective menu that will handle the execution of this action. This
      * allows subclasses of <code>PerspectiveMenu</code> to define custom
      * behaviour for these actions. This value should not be <code>null</code>.
      */
     private final PerspectiveMenu callback;

     /**
      * The descriptor for the perspective that this action should open. This
      * value is never <code>null</code>.
      */
     private final IPerspectiveDescriptor descriptor;

     /**
      * Constructs a new instance of <code>OpenPerspectiveAction</code>
      *
      * @param window
      * The workbench window in which this action is created; should
      * not be <code>null</code>.
      * @param descriptor
      * The descriptor for the perspective that this action should
      * open; must not be <code>null</code>.
      * @param callback
      * The perspective menu who will handle the actual execution of
      * this action; should not be <code>null</code>.
      */
     public OpenPerspectiveAction(final IWorkbenchWindow window,
             final IPerspectiveDescriptor descriptor,
             final PerspectiveMenu callback) {
         super(Util.ZERO_LENGTH_STRING);

         this.descriptor = descriptor;
         this.callback = callback;

         final String label = descriptor.getLabel();
         setText(label);
         setToolTipText(label);
         setImageDescriptor(descriptor.getImageDescriptor());

         window.getWorkbench().getHelpSystem().setHelp(this,
                 IWorkbenchHelpContextIds.OPEN_PERSPECTIVE_ACTION);
     }

   
     /* (non-Javadoc)
      * @see org.eclipse.jface.action.IAction#runWithEvent(org.eclipse.swt.widgets.Event)
      */
     public final void runWithEvent(final Event event) {
         callback.run(descriptor, new SelectionEvent(event));
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.activities.support.IPluginContribution#getLocalId()
      */
     public String getLocalId() {
         return descriptor.getId();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.activities.support.IPluginContribution#getPluginId()
      */
     public String getPluginId() {
         return descriptor instanceof IPluginContribution ? ((IPluginContribution) descriptor)
                 .getPluginId()
                 : null;
     }
 }

